[iforgotpassword]

Haven't used windows in a decade, but there is (was?) a registry setting that would disable focus stealing prevention. Some egregious tools "helpfully" changed that setting for you when you installed them, because they couldn't get focus management to work properly. Maybe it's that?

[ack_complete]

Interference from some program is a possibility, but the relevant foreground lock registry keys seem default on all my systems.